Manual of qualitative analysis / by Robert Galloway.

  • Galloway, Robert.
Date:
1861
Catalogue details

Licence: Public Domain Mark

Credit: Manual of qualitative analysis / by Robert Galloway. Source: Wellcome Collection.

    75/272 (page 57)
    must be added to the B portion, as this reagent precipi- tates baryta only (D 2, E 2,2). To the filtrate from this precipitate (the filtrate will be of a yellow colour, from the excess of chromate of potash, if the baryta has been completely precipitated) add ammonia and oxalate of am- mona, and warm the solution; if a precipitate is produced, it may be due to the presence both of srRonTIA and LIME (E4, F 4) ; if no precipitate is produced, stRONTIA and LIME are absent. Ignite the oxalate precipitate,* if one has been produced, in a small porcelain crucible for a few minutes, in order to convert the oxalates into carbonates. Afterwards, when the crucible is sufficiently cold, dissolve the car- bonates in hydrochloric acid, and evaporate the solution to dryness, in order to expel all the free acid; then dissolve the chlorides in as small a quantity of water as possible, filter the solution, if necessary, through a very small filter, and add to the solution (which must be quite cold before the reagent is added) not too small a quantity of the dilute solution of sulphate of potash,~ after which addition, the solution must be well agitated; if the sulphate of potash produces a precipitate, after the lapse of some time, STRONTIA is present. If the sulphate of potash solution * If the precipitate is so small that it cannot be removed from the filter by means of the platinum Inife, a hole must be made in the apex of the filter, and the precipitate must be washed into the crucible through the hole in the filter by means of the wash-bottle; the water must then be evaporated; and when it is expelled, the dry precipitate must be ignited for several minutes, in order to convert the oxalates into carbonates. + Care must be taken to make the solution of sulphate of potash of the strength directed in the list of reagents. Of that strength, it contains the same quantity of sulphuric acid as a saturated solution of sulphate of lime, contains in a like quantity of liquid; it is, therefore, sufficiently strong to precipitate strontia, but not to precipitate lime. 3 §